Self-improvement guru Steve Pavlina has written up an article about "overclocking" your audio learning; basically, the premise here is to train your brain to listen to audio material at a faster rate than what you're normally used to.
It takes some practice, but for anyone who listens to podcasts or books on CD this is an invaluable time-saver. Maybe now I can finally get around to finishing that 8 hour BBC recording of Lord of the Rings.